1. Field of the Invention
The present invention relates generally to a gas turbine engine, and more specifically to a gravity drained bearing compartment for a gas turbine engine.
2. Description of the Related Art including information disclosed under 37 CFR 1.97 and 1.98
In a gas turbine engine, a rotor shaft is supported by a bearing. A typical gas turbine engine rotor is supported by a forward bearing and an aft bearing. The bearings are supported within a bearing compartment that is drained by gravity. In a gravity drained bearing compartment, it is desirable to reduce the circumferential momentum of the air and oil mixture circulating within the bearing compartment. Separating the air from the oil encourages the majority of the oil to exit the bottom and the air to exit from the top of the bearing compartment. This separation of air and oil greatly reduces the pressure loss common with mixed phase flow. Avoiding this unsteady and high pressure loss associated with the mixed phase flow decreases the probability of flooding the bearing compartment with oil.
One prior art method of achieving this separation of air and oil is to include integral steps in the bearing compartment housing. This method takes up more space as well as makes the part more costly to manufacture.